What I remember from the talk: 1) Don't be a drunken sailor that aimlessly wanders from one topic to another; 2) There are millions of competitions out there, pick one, and become the best. It's an excellent talk.
If you browse for a while and come up with an interdisciplinary fresh idea, I don't think he would mind at all, as long as you stick with it as your main focus :).
I downloaded Hamming’s The Art of doing Science & Engineering - Learning to Learn book only 2 days ago. Skimmed through the chapters on hardware & software.
What you have summarized above is very much applicable to me :) Thanks